Fuel tank pressure sensor?

Tiny
DANIELR
  • MEMBER
  • 2007 FORD F-150
  • 4.6L
  • V8
  • 2WD
  • AUTOMATIC
  • 256,741 MILES
So, my check engine light came on. I plugged in my scanner and it said p0 something for the evap system. So, I looked into it and from what I have read it's a gas cap or ftps so I cleaned the cap real good with wd 40 erased the code and drove. It came back on yesterday. Sa.E code. So now I'm lost. It barely starts now and also the wrench light is on too. Steady not flashing. When I hit the gas to go it hesitates like it's being flooded or something. Here's a video of me starting it this morning. I let go of the key about 1 or 2 sec after I turned it over and it kept turning itself over. It also surges while I'm driving.
Thursday, September 5th, 2024 AT 5:26 AM

18 Replies

Tiny
KEN L
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The code number would help us fix it. I have seen the fuel rail pressure sensor go out and can cause this issue, but it would be better if we had the code. Thanks for the video, it helps. If the engine keeps cranking over a weak battery it can cause this FYI. This guide may help as well:

https://www.2carpros.com/articles/engine-cranks-excessively-before-starting

Check out the images (below). Let us know how it goes.

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Thursday, September 5th, 2024 AT 9:38 AM
Tiny
DANIELR
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P0451, P0642, P1450.
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Thursday, September 5th, 2024 AT 10:36 AM
Tiny
DANIELR
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The codes I'm showing are P0451, P0642 and P1450.
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Friday, September 6th, 2024 AT 9:05 AM
Tiny
KEN L
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Here are the code meanings.

P0451 - Evaporative Emission Control System Pressure Sensor Range/Performance

P0642 - Sensor Reference Voltage "A" Circuit Low

P1450 - Unable to Bleed Up Fuel Tank Vacuum

You might need the PCM reflashed, but these codes are pointing to a faulty fuel tank pressure sensor. Here is the location of the sensor so you can check the connector and if okay I would replace the sensor. Can I ask if the fuel cap is in good condition and has its O ring? Clear the codes once the job is completed. Check out the images (below). Please let us know what happens.
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Friday, September 6th, 2024 AT 5:51 PM
Tiny
DANIELR
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I dropped the tank and tried to replace the sensor. Auto zone Set a non-serviceable part O'reilly's can't find it at all.
And the one that I got off Amazon. I'll send you some pictures of right now. It's their the plugs different. Just a little bit like the nipples on the plastic piece. They're different spots on the old one in the new 1. So I could make it fit but I don't know if the wiring is going to be the same as hot ground negative. Or whatever and if u will notice the prongs are in different positions as well.
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Thursday, September 12th, 2024 AT 11:27 AM
Tiny
KEN L
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That sensor is for the tank, the one you need is in the fuel rail, the fuel tank pressure sensor will not keep the engine from starting but the fuel rail sensor will.
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Thursday, September 12th, 2024 AT 4:07 PM
Tiny
DANIELR
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It never had trouble starting. Except the first start of the day. And you even told me and sent me a diagram of that sensor. The fuel tank pressure sensor. That was the code it threw and everything. So, do I need to get the fuel rail pressure sensor?
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Thursday, September 12th, 2024 AT 7:21 PM
Tiny
KEN L
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Okay, if the truck starts okay then you are on the right track. Continue with the sensor. I was going off of "It barely starts now and also the wrench light is on too. Steady not flashing. When I hit the gas to go it hesitates like it's being flooded or something." And then the video. In the first post.
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Friday, September 13th, 2024 AT 8:22 AM
Tiny
DANIELR
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Yes sir. It was hard to start first thing in the morning. Now it's ok. But the engine light is still o. And the wrench light is still on. I plugged my obd reader into it and erased the codes after I changed that pressure sensor. And after driving it they are both back on. And it's showing about 10 codes now. Things like maf sensor, pcv valve, blower mower circuit, egr valve, o2 sensor. But the P0451 or what ever it was is gone now.
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Friday, September 13th, 2024 AT 2:21 PM
Tiny
KEN L
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Hmmm thats a good one, I am wondering if the PCM needs to be reflashed, it should not have done that. I would try a hard system reboot to see what happens, here is a guide to help:

https://www.2carpros.com/articles/step-by-step-guide-performing-a-hard-system-reboot-for-your-vehicles-electronics-systems

Please go over this guide and get back to us.

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Saturday, September 14th, 2024 AT 9:16 AM
Tiny
DANIELR
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So one of the codes showing is P0480 engine coolant blower motor. Circuit malfunction. Now it's my understanding that that code would be for an electric fan. Mine isn't electric.
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Tuesday, September 17th, 2024 AT 7:50 AM
Tiny
KEN L
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Yep, that is strange, I would remove the electrical connectors for the PCM and check for corrosion which can cause all kinds of strange problems. If everything looks okay I would get a rebuilt preprogrammed PCM by searching Google or Ebay. Here is the PCM location and how to change it out. Check out the images (below). Please let us know what happens.
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Tuesday, September 17th, 2024 AT 9:36 AM
Tiny
DANIELR
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So my scanner showed me a few codes P0102, P0135, P0155, P0403, P0443. So I changed the MAF sensor and all four 02 sensors and erased the codes. Drove the truck a while and checked and it's still showing those same codes. I'm changing the egr valve tomorrow. Buy I don't understand why.
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Tuesday, October 22nd, 2024 AT 6:45 PM
Tiny
KEN L
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Did you change out the PCM? I have seen a bad PCM cause these problems.
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Wednesday, October 23rd, 2024 AT 9:36 AM
Tiny
DANIELR
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No sir. I'm trying to avoid that. I am gonna probe the maf sensor plug and see if it's getting the 5v it needs. Cause I was told that all those sensors I am dealing with basically use the same signal wire.
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Wednesday, October 23rd, 2024 AT 10:28 AM
Tiny
KEN L
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That is correct, the MAF shares the same 5 volt reference voltage.
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Wednesday, October 23rd, 2024 AT 11:06 AM
Tiny
DANIELR
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Ok I'm gonna check that and see if it's getting it from the pcm. Could u perhaps send me a wiring diagram from the pcm to the MAF
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Wednesday, October 23rd, 2024 AT 2:04 PM

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